How to make a Island in SbuilderX

I can't get an island in fsx I am using sbuilderX on fsx.

I Created a polygon then I right click and set as hole just like the tutorial said, But nothing appeared.

The image bellow is the island I was trying to make.
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It can only be a hole, if there is something for it to be a hole in. In this case it would be another polygon that was water, thus allowing the land to be cut from the water polygon. Depending upon the coastline for the area, excluding the existing water and making a new polygon to replace it may not be too great an effort.
I still couldn't get to work. I tried placing the water polygon below the island polygon as you said and then I set the island polygon to set as hole.

Honestly I'm lost, Today is the first day I every used the program.Can someone give me a step by step tutorial on how to make an island?
The first thing you have to do, is analyze what is currently there in FSX. For example, let's assume it is a lake or ocean area, currently shown as water in FSX, and you now want to place an island in that water.

There are a couple of possible approaches, but I think the main options would be to 1. remove the existing water area, and replace it with water that includes the island, or 2. place an island by drawing land area on top of the existing water.

There are a couple of considerations:

method 1 has the advantage, that it will allow any elevation mesh that exists for the island to be shown. Of course, if there isn't any mesh, or your island is fictional that isn't any benefit. The disadvantage, is that you have to re-create the existing water body in its entirety (the typical water body is a polygon that is contained within a QMID 11 boundary -- these boundaries are shown by turning on the QMID display in SBX). In the unlucky event that your island crosses into 2 or more different QMID 11 cells, this can result in quite a bit of rework.

method 2 has the advantage of leaving the existing water body intact, but at the expense of having to recreate the elevation mesh of the island (if you want your island to be flat, that isn't a big problem of course).

To do method 1, first you need to be able to recreate any coastline that your water body must provide (including your new island). this can be done by using a satellite image as a background and tracing a coastline, or loading the default (or other terrain file that supplies the water body) in the sdk tmfviewer program, taking a screenshot that covers the water body, and using that as a map in SBX (You can set a QMID 11 grid in tmfviewer as well, and use that to calibrate the map). Once you have your background or map, you can create a rectangle area within the water body (doesn't need to be exact) set to exclude hydro polygons. That will get rid of the water body. Now you create new polygons tracing the coastline in the background or map. Where the new water body is bounded by one of the QMID 11 grid boundaries, I just extend the polygon out to the neighboring cell, and then use the "clip" function to slice the polygon accurately at the border.

Once you have created the water body, the use the same technique to create the island. When you finish the island, select it and use the context menu option to set as hole, then click on the water polygon to set it as the parent of the hole. (A hole must be completely within its parent and can only have 1 parent).

To do method 2, just trace out the coastline of your island as a polygon, this time set to Legacy_LWM_Land_Flatten. You must also set your altitude elevation or it will be at the same elevation as the water body.

With either method, at this point there will probably be no visible land, since there probably isn't any landclass defined for the area of your island. You can either use the landclass function in SBX to place appropriate landclass textures on your island (make sure the number of landclass tiles you define extend out from your island a bit or you might not get 100% coverage in the sim due to how FS blends landclass textures together), or you can create a copy of your island poly and place right on top of your original one, but set it to a specific landclass texture.

If you want a shoreline, possibly with breaking surf, you must select the poly for your island, or other coast, and use the "make line" function to create a matching line, which you set to an appropriate shoreline. Depending on your poly configuration, you might be missing a segment of the coastline (where the line starts and ends) which you can draw by hand, and you might need to reverse the direction of the line if your beach/surf is on the wrong side.

When working with shorelines and matching island coasts, it can be helpful to use the "view" menu to turn polygons or lines on/off to declutter your view. Be mindful of what tool you have active: selection/pointer, line, or poly as your results of any operation might depend on which tool you have active.

scott s.
Scott, I have been trying your Method 2, so far without success.

I created an island polygon, elevated a few feet above the water level and set it to Legacy_LWM_Land_Flatten. Then placed a landclass poly on top of that.

The island appears, but merely as a hump in the water, without landclass texture.

Also tried a landclass tile instead of the poly -- no joy there either.

Any suggestions where I might be going off course?

it seems as if you have a similar problem to mine.
Did you ty to land on the appearing island? My island appears too, but
my airplanes drown on the surface. The funny thing is that airplanes with floats do not drown.
So it must be a problem of the default ground (which was water).

Maybe someone has an idea!

The only solution that worked for me was Method 1.

But tedious recreating the new hydro poly coastline over an entire QMID 11 region (about 20km).

Still hoping someone can confirm success with Scott's simpler Method 2.

I have a problem creating an island too.

I followed the tutorial Terrain Design for Sbuilderx, I can see the island but it looks like the water is still there. My plane floats instead of rolling. I have no idea what I did wrong.
I also used the Alan Blencowe's example to compare with my creation, and I can't see what i am missing. :confused::(

I tried as much as I could and still don't get it.

What I do:
1) create an exclude all terrain polygon. The QMID11 is fill with land as it should.
2) create an hydro polygon to put back water.
3) make a hole inside the hydro polygon(parent).

The island/hole shows up but my planes splash on it :confused:

It's weird because I looked at others sample such as the island in North West Australia and I really don't see what am I missing... Any help would be great!
1. I use exclusions specific to the desired purpose, which in this case is to exclude the water, not all terrain items.

2. Once you have made the hole polygon and associated it with the parent polygon, and it can take a very precise click to make sure you've nailed the parent polygon, I take a copy of the hole polygon and reassing some type of land class to it. Then move it on top of the original hole polygon.

But it has been a while since I've done this type work in SBuilderX.


Staff member
Resource contributor
Hi all.

Exclusion polys are best thought of as poison... they destroy what they touch. A small exclusion will destroy another poly or line up to it's QMID11 bounds.

For an island in vacant water, a small triangle can remove all terrain in that QMID11:

After you exclude the terrain, you need to alter the landclass ( because the LC from the default is most probably set to water! )

Then make a new hydro poly, and create a hole in it for the landclass to show through. You'll end up with 2 BGLs. One for landclass and one for the exclude/hydro polys.

Solid land, due to the landclass. ( note that "mangrove" has some water characteristics! ).



Imageshack is really good for storing images, and SkyDrive is great for storing files, without burdening server space.
The only solution that worked for me was Method 1.

But tedious recreating the new hydro poly coastline over an entire QMID 11 region (about 20km).

Still hoping someone can confirm success with Scott's simpler Method 2.

ISTR people have been using something along the lines of method 2, which uses the FS9 legacy water/land mask, but I did some experiments and couldn't get good results.

For my part, I only use the FSX methods, that is exclude default terrain, add landclass definitions, place hydro poly (fill QMID 11) and then create holes for islands if within a single QMID 11. As you say this has the drawback of having to recreate an entire coastline if one exists in the QMID 11 (and I did a scenery of Incheon Airport on an Island in Korea, and it's a lot of work if you can't get a vector file of good coastline data, so I am aware of this.) I wish we had a way of importing stock data like in FS9, so that we could just reuse the stock shoreline where we aren't working on it.

scott s.
Thanks, Scott -- glad to hear it's not just me!

Agreed, it would be great if we could import FSX bgls, as we did in FS9. In addition to recreating shorelines, it would sure help in identifying mismatches between default FSX scenery and the real world.

I'm working a similar problem in Vermont, where I want to replace an existing Island with one that looks more like the real thing. Using the QMID 11 approach requires that I redraw most of Vermont, lol. The Island in question is in close proximity to other land masses and blocking an entire QMID sector just isn't feasible.
Look at the cvx file in trmfviewer and see how big the actual hydro poly is that contains the island. For example often it is drawn as QMID13 which reduces the scope of the problem.

scott s.
Hi all,

I tried the above methods for making an island, and of course none work. I have 4 polys in this order:

- Exclude_All_Water_Polygons (small triangle in center of QMID11 rectangle)
- LC_Grass @ 20ft (bigger than the excluded QMID11 rectangle)
- Hydro_Default_Perennial (to fill up the excluded QMID11 rectangle)
- Hole (a randomly shaped poly, within the QMID11 rectangle, with as parent the Hydro poly)

I see the shape of the island, but it is not raised, and planes sink through. Does it matter if I draw the polys clockwise or anti-clockwise?
Could someone please take me by the hand and guide me towards a landable island? (If creating one is even possible....)


Staff member
Resource contributor
Hi Pierre.

You could export an SBX file, grab the BGL files, and an FSX FLT file, and zip them all up and attach to a post. Then we could actually provide some comment.

Hi again,

I can compile only 1 BGL file, and I can't find any FLT files related to this project.
I did include the SBX and SBP files.

I don't know why a FLT file is needed, but the island is at N43 W69.

Is there anyone with a working solution?


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